The effect of gamma irradiation on the time-course mortality and radiosensitivity indices in 1-and 10-day-old adult Tribolium anaphe , T. brevicornis, T. castaneum, T. destructor and T. freemani, was studied. Longevity was always adversely affected by irradiation, and it was linearly dependent on the dose rate. Except for 10-day-old adults, all the insects died within 12 weeks of -irradiation at 4 and 5 krad. In addition, T. destructor was markedly more radioresistant at all dose levels, and

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... ed longer than the other species. The mean survival times of adults were generally shorter in females than in males for all species. The radiosensitivity indices did not vary widely among the species, but decreased as the dose increased in all the species, indicating that the resistance of the species was dose-dependent.